Methods of determining skeletal maturity

Abstract

The present invention provides methods to determine skeletal maturity.

1 . A method of determining skeletal maturity in a subject, comprising measuring the level of IGF-1 in a tissue or fluid sample, wherein an elevated level of IGF-1 post-puberty indicates that said subject has not reached skeletal maturity. 
   
   
       2 . The method of  claim 1 , wherein said level of IGF-1 post-puberty exceeds 250 μg/L. 
   
   
       3 . The method of  claim 1 , wherein said subject is suffering from or at risk of developing a mandibular or facial growth abnormality. 
   
   
       4 . The method of  claim 1 , wherein said method does not comprise x-ray examination of a cervical vertebra. 
   
   
       5 . A method of identifying the skeletal maturity stage of a mammal, comprising the steps of: determining the level of IGF-1 in said sample, wherein levels ranging between 140 and 260 ug/L indicates that a mammal in prepubertal stage is at cervical stage (CS) 1 or CS2, levels ranging between 270 and 320 ug/L indicates that a mammal in early pubertal stage is at CS3, levels ranging between 320 and 380 ug/L indicates that a mammal in pubertal stage is at CS4, levels ranging between 380 and 500 ug/L indicates that a mammal in late pubertal stage is at CS5, and levels ranging between 200 and 400 ug/L indicates that a mammal in post pubertal stage is at CS6 
   
   
       6 . The method of  claim 5 , wherein a mammal having IGF-1 levels ranging between 260 and 500 ug/L and identified as being at CS1, CS2, CS3, CS4, or CS5 is selected as a candidate for a medical procedure that involves residual bone growth in said mammal. 
   
   
       7 . The method of  claim 5 , wherein a mammal having IGF-1 levels below 280 ug/L and identified as being at CS6 is selected as a candidate for a medical procedure that does not involve residual bone growth. 
   
   
       8 . The method of  claim 6  or  7 , wherein said bone growth is facial bone growth. 
   
   
       9 . The method of  claim 8 , wherein said facial bone growth is mandibullar growth. 
   
   
       10 . The method of  claim 6  or  7 , wherein said medical procedure is a dental procedure. 
   
   
       11 . The method of  claim 10 , wherein said dental procedure is an orthodontic procedure. 
   
   
       12 . The method of  claim 10 , wherein said dental procedure is a tooth implant. 
   
   
       13 . The method of  claim 1 , wherein said biological sample is serum, blood, or saliva. 
   
   
       14 . The method of  claim 13 , wherein said blood is obtained by blood spotting. 
   
   
       15 . The method of  claim 5 , further comprising obtaining a hand-wrist radiograph from said mammal. 
   
   
       16 . The method of  claim 15 , wherein said hand wrist radiograph is evaluated using the Greulich and Pyle technique or the Fishman technique. 
   
   
       17 . The method of  claim 5 , wherein said mammal is a human. 
   
   
       18 . The method of  claim 5 , wherein pre-pubertal stage, pubertal stage, late pubertal stage, and post-pubertal stage are identified by physical characteristic of said mammal. 
   
   
       19 . The method of  claim 18 , wherein said physical characteristic is a sexual characteristic. 
   
   
       20 . The method of  claim 5 , wherein said pre-pubertal stage, pubertal stage, late pubertal stage, and post-pubertal stage are identified by the chronological age of said mammal. 
   
   
       21 . A method of identifying the skeletal maturity stage of a mammal, comprising the steps of:
 (a) providing a biological sample from a mammal;   (b) determining the level of IGF-1 in said sample; and   (c) repeating steps (a) and (b) at one or more time intervals, wherein an increase in IGF-1 levels over time indicates that said mammal is between cervical stage CS1 and CS5 and a reduction of IGF-1 levels over time indicates that said mammal is between CS5 and CS6.   
   
   
       22 . The method of  claim 21 , wherein said repeating is performed approximately every year from the time said mammal is in prepubertal stage. 
   
   
       23 . The method of  claim 22 , wherein said repeating is performed approximately every six months. 
   
   
       24 . The method of  claim 21 , wherein a mammal whose IGF-1 levels are increasing over time and is identified as being at CS1, CS2, CS3, CS4, or CS5 is selected as a candidate for a medical procedure that involves residual bone growth in said mammal. 
   
   
       25 . The method of  claim 21 , wherein a mammal identified as being at CS6 and whose IGF-1 levels are less than 280 ug/L is selected as a candidate for a medical procedure that does not involve residual bone growth. 
   
   
       26 . The method of  claim 24  or  25 , wherein said bone growth is facial bone growth. 
   
   
       27 . The method of  claim 26 , wherein said facial bone growth is mandibullar growth. 
   
   
       28 . The method of  claim 24  or  25 , wherein said medical procedure is a dental procedure. 
   
   
       29 . The method of  claim 28 , wherein said dental procedure is an orthodontic procedure. 
   
   
       30 . The method of  claim 28 , wherein said dental procedure is a tooth implant. 
   
   
       31 . The method of  claim 21 , wherein said biological sample is serum, blood, or saliva. 
   
   
       32 . The method of  claim 31 , wherein said blood is obtained by blood spotting. 
   
   
       33 . The method of  claim 21 , further comprising obtaining a hand-wrist radiograph from said mammal. 
   
   
       34 . The method of  claim 33 , wherein said hand wrist radiograph is evaluated using the Greulich and Pyle technique or the Fishman technique. 
   
   
       35 . The method of  claim 21 , wherein said mammal is a human. 
   
   
       36 . The method of  claim 21 , wherein pre-pubertal stage, pubertal stage, late pubertal stage, and post-pubertal stage are identified by physical characteristic of said mammal. 
   
   
       37 . The method of  claim 36 , wherein said physical characteristic is a sexual characteristic. 
   
   
       38 . The method of  claim 21 , wherein said pre-pubertal stage, pubertal stage, late pubertal stage, and post-pubertal stage are identified by the chronological age of said mammal.